cleanup the introspection API

Author: martinbonnin

libraries/apollo-ast/src/commonMain/kotlin/com/apollographql/apollo3/ast/api.kt

@@ -11,6 +11,8 @@ import com.apollographql.apollo3.ast.internal.LexerException
 import com.apollographql.apollo3.ast.internal.Parser
 import com.apollographql.apollo3.ast.internal.ParserException
 import com.apollographql.apollo3.ast.internal.validateSchema
+import com.apollographql.apollo3.ast.introspection.toGQLDocument
+import com.apollographql.apollo3.ast.introspection.toIntrospectionSchema
 import okio.Buffer
 import okio.BufferedSource
 import okio.Path
@@ -19,6 +21,22 @@ import okio.use
 import kotlin.jvm.JvmMultifileClass
 import kotlin.jvm.JvmName
 
+
+@ApolloExperimental
+fun Path.toSchema(): Schema = toSchemaGQLDocument().validateAsSchema().getOrThrow()
+
+/**
+ * Transforms the given path to a [GQLDocument] without doing validation
+ */
+@ApolloExperimental
+fun Path.toSchemaGQLDocument(): GQLDocument {
+  return if (name.endsWith("json")) {
+    toIntrospectionSchema().toGQLDocument()
+  } else {
+    parseAsGQLDocument().getOrThrow()
+  }
+}
+
 /**
  * Parses the source to a [Schema], throwing on parsing or validation errors.
  *